A cantilever-type screen printing machine is one of many important printing machines and is particularly suitable for precision printing on circuit boards. This type of screen printing machine typically includes a platform having an upper surface defining a printing bed, an elevating slide base provided to one lateral side of the platform, a transverse slide base mounted on the elevating slide base to move leftward and rightward, a cantilevered printing head forward extended from the transverse slide base and adapted to slide leftward and rightward, a cantilevered arm forward extended from each lateral side of the transverse slide base, and a clamping support is provided at a lower side of each of the two cantilevered arm for holding a screen frame between the two cantilevered arms. When an object to be printed is positioned on the printing bed, the printing head is pneumatically or electrically driven to transversely move and scrape ink on the screen. At this point, the printing head produces a downward pressure, causing the ink to penetrate through the screen to the object to be printed and create a printing effect via a pattern on the screen.
Currently, there are many different types of screen printing machines available in the market, including cantilever type, four-pillar type, electric type, electric vertical type, pneumatic type, etc. All these types of screen printing machines have almost the same elevating mechanism and driving means. Moreover, the conventional screen printing machines all are vertically elevated and lowered in the process of printing. Generally, the screen printing machine includes the operating procedures of applying an adequate amount of ink on the screen, driving the printing head to reciprocate on the screen from one side to the other side for the ink to penetrate the screen to the object to be printed, actuating the elevating slide base to vertically elevate the printing head and the screen frame, sliding the printing head to an initial position, and lowering the elevating slide base again to start the next printing. Each time the printing is completed, an operator would check the printing quality by removing the printed object from a very limited space between the printing bed and the elevated screen and printing head. Due to the limited space, it is relatively difficult for the operator to position and remove the objects to be printed or having been printed, and the productivity of the screen printing machine is adversely affected.
Since the elevating and the transverse slide base in the conventional screen printing machines are pneumatically driven and could not be quickly actuated under control, the conventional screen printing machines fail to achieve fast and high-quality printing to satisfy the market demands.
It is therefore desirable to improve the conventional screen printing machines to overcome the above-mentioned drawbacks.